Method of and apparatus for heat-treating structural members



Patented Apr. 26,1921.

4 SHEETS SHEET 1.

A. 5. AND PfMACDONALD. METHOD OF AND APPARATUS FOR. HEAT TREATING STRUCTURAL MEMBERS.

*A. 8. AND H.'-R.1 MACD.ONALD. METHOD omwn APnAaATus FDRiH-EA T :TREAiTlNG STRUCTURAL MEMBER'S. APPLICATION iflliEDMER-JB. 1918.

1,376,106, Patented Apr. 26,1921.

4 SHEETS-SHEET 2.

I J lire/Woes Q /4' jZg Mal] A. S.-AND H. P. MACDONALD.

METHOD OF AND APPARATUS FOR HEAT TREATING STRUCTURAL MEMBERS. APPLICATION FILED APR. 18, 1918.

. 1,376,106. Patented Apr. 26,1921.

4 SHEETS SHEET 3.

f/VVE/VTORS A. S. AND H. P. MACDONALD. METHOD OF AND APPARATUS FOR HEAT TREATING STRUCTURAL MEMBERS.

APPLICATION FILED APR. 18, 1918.

Patented Apr. 26, 1921.

4 SH.EETSSHEET 4.

uvrswro/as fizz/rum WM' 61,12; @7435.

a .UNI-TED- STAT-ES PATENT OFFICE.

ANGUS S. MACDONALD, OF GREAT NECK STATION, NEW YORK, AND HARRY P. MAG- DONALD,

OF MONTCLAIR, NEW JERSEY, ASSIGNORS TO THE SNEAD &;CO, IRON worms, or JERSEY CITY, NEW JERSEY, A CORPORATION or NEW JERSEY.

Specification of Letters Patent.

Patented Apr. 26, 1921.

Application filed April 18, 1918. Serial No. 229,241.

T 0 all whom it may concern:

Be it known that we, ANoUs ALD and HARRY P. MACDONALD, both citizens of the United States, respectively residing at Great Neck Station, county of Nassau,

and State of New York, and at Montclair, county of Essex, and State of New Jersey, have inventedcertain new and useful Im- ,provements in Methods of andApparatus for Heat-Treatin Structural Members, of which the following is avspecificatron.

This invention" has relation to a method of and apparatus for the heat treatment of" Here- 7 rails and similar structur'al members. I tofore, in so far as we are aware, steel rails and other structuralmembers in commercial practice have not been, given any heat treatment, such for example as heating to the critical point, commonly designated as the point of recalescence, and then quenching, for the reason that conventional methods and apparatus are unsuitable for the heat treatment of rails and similar structural members. Thus, for example, a steel rail because of its size and weight would become distorted and bent in removal from the conventional furnace in which the heat is applied externally, if it had not already become distorted during the heating operation. Similarly, the irregularities in cross section would in all probability result in distortion if conventional quenching methods were followed. A further deterrent factor is to be found in the great cost which would be involved in the heat treatment of steel rails by standard 'methods.

By the improved method and apparatus hereinafter described we overcome the difficulties hereinbefore noted with respect to standard methods of heat treatment, and make it possible to heat treat rails economically and expeditiously and by very simple means.

The apparatus which we prefer in carrying out our method is shown in the, accompanying drawings wherein Figure 1 is a front elevation of the heating and quenching apparatus; Fig. 2 is a side elevation of Fig. 1; Fig. 2 is a figure showing one form of mechanism employed in supporting and shifting the rail being treated; Figs. 8 and 4c are an enlarged plan and side elevation of certain of the means for supporting the rail in the heating apparatus; ig. 5 is a side S. Maooon- Figs. 1 and 2 on the lines VI-VI and VI -VI*respect1vely; Fig. 7 is a cross sece.

tion through a modified heating apparatus having combined therewith means for quenching the rail therein; Fig. 8 illustrates a modification of the means" for quenching the rail after heat treatment.

Our improved method will be best understood from the description of the apparatus which now follows.

Referring particularly to Figs. 1, 2 and prises a vertically arranged main frame or su porting structure A which may be suitab y braced in any preferred manner. Associated with the frame is a box B hinged as indicated at 7 so as to be swung open to receive the rail C, the box being filled, if desired, with insulating material, such for example as an asbestos lining 8 adapted to retain the heat. Adjacent the ends of the box B and supported from the framework A are a pair of supporting jaws or contacts D and E, such contacts being adapted to receive and embrace the ends of the rail and being connected to a suitable source of electricity by the leads 9 and 10, one of such leads having means for regulating the voltage or the amperage, or. both, as diagram-.

inatically indicated at 11. The contact E, for reasons which will hereinafter appear, is mounted on the frame A so as to have rela tive movement with respect to the contact D, the connection between the contact E and the frame permitting the contact to slide in the frame (see particularly Fig. 5). Intermediate the contacts D and E, and at any number of desired points, the rail may be supported in the heating apparatus by means of clampin devices diagrammatically indicated by in Figs. 1 and 2, and in detail in Fig. 6

Referring now to the contacts D and E and the mechanism for operating the same,

2% it will be seen that the apparatuscomp the bearlng 14'. At its outer end, the stem will move the ,jaws to open position, and

.which permits the contact 15, is provided with an eye 16 in which is fitted an eccentric or cam member 17 keyed to the shaft 18, such shaft being turned by any desired. means, such, for example, as the operating lever 19. The shaft is suspended from the bearing casting 14: of the upper contact D by means of the nut 20, and the bearing 14' of the lower contact is slidable on the shaft 18. When the shaft 18 is rotated in one direction the cams 17 when the shaft is rotated in theopposite direction, the jaws 13 will be moved toward the jaws 12. The contact E differs from contact D in that its base 14 is bolted to the frame A in such manner that the bolts have lost motion (see- Fi 3, 4 and 5) to sink as the article being treated expands and thus prevents distortion thereof.

In placing a rail in position in the heating apparatus, the box B is first o ned and the jaws 13 retracted, after whic the rail is moved in position by means-of any preferred apparatus, such, for example, as the crane hoist mechanism G 1 (Fig. 2), the tongs 21 which are adapted to grasp the untrimmed end a of each rail, after being thus positioned,

. struction of the. clamps the jaws 13 are then advanced to clamp the ends of the rail in the contacts D and'E, after which the box is closed. The rail is now supported by the hoist and the jaw contacts D and E, and it may also be clamped intermediate its ends by the clamps F herein-.

before described.

ere intermediate clamps are employed We prefer to have them operated from the shaft 18 in the same manner as the contacts D and E, so that all clamps will be simultaneously closed and released. The detailed confrom that of the contacts D and E in that it is desirable to have a minimum surface engagement with the'rail in order to insure more uniform heatin for the reason that the rail Wlll be relative y cool at points of surface contact, when electricity is used as the heating medium. The clamping elements'F are also mounted for slight movement in the' frame A in the same manneras the contact E and for the same reasons; namely, to per-- mit'of the expansion of the rail as it is being heated, so as to prevent the buckling which would otherwise take lace.

The fact that the rail is supported vertically and substantially suspended. from above in itself assists in preventing warping and the clamps F and contact preventing such warping and and distortion, E also assist in F, however, difi'ers distortion. This will be clear from the fact that the clamps F and contact E, while permitting the rail to expand, firmly hold the rail against all other forms of movement.

F or a tempering operation, assuming that the rail is in the heating apparatus, the current is turned on and the rail is heated by its internal resistance to the passage of the current therethrough, the current being continued until such time as the temperature reaches or passes through the period of de calescence, and when this point is reached, the heat is cut oil", either by discharging the rail from the heating apparatus, or by cutting off the current, orv by simultaneous discharge and cutting off of the current, as will be ointed out.

n the path of movement of the contact E is a movable abutment or trip 22, which is trip is released by the engagement of the abutment 22, the welght 25 will also rotate the shaft 18 so as to release the contacts and clamps, after which the rail is lowered into a tubular receptacle 28, which is located immediately beneath the contact E and is filled with a suitable quenching medium, such, for

example, as oil. In lowering the rail into the bath, a uniform velocity should preferably be maintained. i

If desired, the mechanism shown in Fig.

5 may be employed, in which case the automatic control device may be dispensed With.' In the arrangement shown in Fig. 5,

an indicatin device H is operatively associated with t e lower contact E by means of a gear segment 29 which engages a pinion 30 operating a pointer 31. The dial of the indicator may be graduated in any desired-'1 manner, but if the movement of the contact E be sufficiently amplified, the pointer 31' will indicate the time when the metal reaches the critical point, because at such a point expansion'temporarily pauses, for the reason that at such critical period, the metal will temporarily absorb heat units without a corresponding rise in temperature. Therefore, when the operator notes a substantial pause in the movement of the ointer 31, he will know that the rail has con heated to the proper point and can manually operate the release and lower therail intothe bath.

It may be desirable to quench the rail andparwhile it is in the heatin apparatus,

ticularlywhile it is sti lin a clamped'posit1on in' orderto lpreventa possible warping during the quenc mg operation which might result from irregularity in section. To

accomplish this, we provide the arrangement shown in Fig. 7, in which the interior of the box 13 is provided with a plurality of pipes 32 each having a plurality of jets 33 adapt ed to direct a spray of quenching medium against the rail, the quenching medium being supplied by pipe 34 controlled by a valve 35. It will be noted that the jets are so located and are of such dimensions that the greatest quantities of spray are directed against the thickest portion of the rail. Stated in other words, a differential spray is employed for the purpose of obtaining uniform quenching to eliminate the possibility of warping or distortion. As hereinbefore noted, the clamping of the rail between the contacts D and E and the clamps F will assist in preventing warping during the quenching. It will be obvious that various forms of mechanism may be employed for securing this differential spray.

In Fig. 8 we have shown the heating apparatus with a spray chamber B immediately adjacent thereto and in such relation that the rail may be carried laterally from the heating apparatus into the spray chamber by means of the crane hoist shown. For this purpose the chamber is split, the parts being hinged so that one of the same may be swung to one side, as illustrated, to permit of the introduction of the rail.

From the foregoing it will be seen that we have provided a very simple method and apparatus for heat treating rails and by means of which the rails may be heat treated both quickly and economically. In addition to these advantages, it is to be noted that the rail is heated in a vertical position, substantially suspended from above, in such a manner that regardless of whether the rail is quenched by lowering into a bath or by spray directly in the heating apparatus or by lateral transfer into a quenching cham-- her, there is no liability of distortion or bending of the rail in the handling thereof. Furthermore, by suspending a rail the tendency of the rail will be to maintain its straightness. Another advantage incident to our arrangement is that a very convenient means is provided for supporting the rail clear of the main supporting structure which thus greatly simplifies the heating operation as the rail is in contact but for a fraction of its length. The heating of the rail is uniform throughout, and it is possible to secure uniformity of results through any'number of successive operations which is of the greatest importance. Heat treated steel rails and other structural members will, of course, be far superior to those now commercially used.

We also propose, in some cases, to carry out =the heat treat-ment directly after the rail or other structural member passes from situ.

2. A combined heating and quenching apthe rolling mill and while it is still hot, this wise occur, if the rail were cold, are avoided,

in addition to which it is to be observed that the heat treatment of the rail while still hot would tend to produce uniformity.

In carrying out this part of our invention we prefer to allow the steel, after being passed from the rolling mill on to a table or other support, to cool below'the point of recalescence, after which the electrical contacts would be made, in a manner analogous to that already described, and the current turned on until the decalescent point was passed. The piece is then cooled by plain or differential spray or by immersion in the tank, in analogy to the steps already described, it being preferred that the quenching should continue for such length of time as is necessary to obtain the desired hardness, but still leaving enough residual heat to draw the. temper and also perhaps to allow the piece to be straightened, if it had become bent.

As before described, we prefer to clamp the piece to prevent warpingboth during heating and quenching, and during the electrical heat treatment it is preferred that the piece be kept under tension to promote straightness.

It is to be understood that departures may I be made in details of our invention without departing from the scope thereof as herein defined, and in addition, the terms heat treating is employed in its broad sense.

We claim:

1. A combined heating and quenching apparatus for the heat treatment of metallic objects, comprising in combination means for supporting the article, means for heating the article by its internal resistance to the passage of a current of electricity therethrough, and means whereby a quenching medium may beapplied to the article in paratus for the heat treatment of metallic objects comprising a main structure having means for supporting the article clear of the main structure, means for heating the. article by its internal resistance to the passage of a current of electricity, and means for applying the quenching medium to the article in situ.

3.'An apparatus for heat treating rails comprising in combination a main support ing structure, means for heating the rail substantially throughout and means for supporting the rail in the main structure a must distortion but permitting expansion the rail during heating.

4. An apparatus for heat treatlng rails comprising in combination means for heating the rail, means for quenching the rail substantially uniformly and means for sup--' porting the rail against distortion during the quenching, but permitting contraction thereof. 1 a

5. An apparatus for heat treating rails comprising in combination'meansfor heating therail, and'nieans for differentially applying a quenching medium to the various surfaces-thereof to obtain substantially uniand means for passing an electric current 'throu h the rail.

7. apparatus for heattreating rails comprising in combination a main structure, means for sus ending the rail in said main structure; an a plurality of supporting adapted to support the rail against distortion but permitting expansion thereof, and 'means for passing an electric current through the rail.

8. The herein described method of handling a rail for heat treating and. quenching purposes which consists in suspending the rail from an end thereof and performing the heat treating and quenching operations.

9. The herein described method of. heat treating rolled metallic objects which consists in heat treating the object after it has passed from the rolling mill but after it is cooled below the point of recalescence, and then in quenching the object to a point where the residual heat is still SllffiClGIlt to draw the temper. I In testimony whereof, we have hereunto signed our names.

. ANGUS MACDONALD HARRY P. MACDONALD. 

